Band spinning apparatus



Sept. 13, 1955 R. P. PIPEROUX ET Ax.

BAND SPINNING APPARATUS 2 Sheets-Sheet l Filed Jan. 24, 1951 G NU SXR S R T Y OUS E NmmR R E A O P T VIT. T mPf PA n? NBB ,EO RR 1 /f f/ /f Sept. 13, 1955 R. P. PIPEROUX ET AL BAND SPINNING APPARATUS 2 SheetsSheet 2 Filed Jan. 24, 1951 FIG.6.

INVENTORS. RENE P. PIPEROUX ROBERT T. ARMSTRONG Y f f/M ATTOR EYS.

United States Patent O BAND SPINNING APPARATUS Rene P. Piperoux, Radbum, N. I., and Robert T. Armstrong, Pearisburg, Va., assignors to Celanese Corporation of America, New York, N. Y., a corporation of Delaware A Application January 24, 1951, Serial No. 207,514

1 Claim. (Cl. 18-8) This invention relates to the preparation of flamentary materials and relates more particularly to an improved apparatus for the preparation of iilamentary materials by the band spinning process.

In the preparation of iilamentary materials such as yarns, laments, bristle, straw, ribbon and the like by the band spinning process, a band of filament-forming material is entered at a constant rate by suitable feed means into a heated melting tube having a passageway extending therethrough and leading to a spinning jet containing at least one spinning orifice, the entrance portion of the passageway being of such size and shape as approximately to t the band. The filament-forming material melts and is brought to the proper temperature for spinning as it traverses the passageway of the Amelting tube to the spinning jet, and the molten filament-forming material is forced through the spinning orifice by the pressure developed by the incoming band, which acts as a continually renewed piston. Among the filament-forming materials that may be spun in this manner are, for example, the polycarboxyamides, polysulfonamides, polysulfones, polyurethanes and polytriazoles.

As the band of filament-forming material enters the passageway leading to the spinning jet, melting-will begin at the surface of said band and will progress gradually toward the center thereof. -Since the heat conductivity of the molten Element-forming material is'quite low, a considerable period of time will be required to effect the complete melting of the band and to bring the melted filamentforrning material uniformly to the proper temperature for spinning. If the filament-forming material reaching the spinning jet contains any unmelted material, or if the temperature thereof is non-uniform, there-,will be produced undesirable variations in the denier of the lamentary material and the continuity of the spinning may be interrupted. In addition, when theband feed rate is high, the unmelted portion lof the band will become extremely long and jamming ofthe band and interruption of the continuity of the spinning may occur if the un;- melted portion of the band approaches or reaches the spinning jet. 1

It is an important object of this invention to provide a novel apparatus for the production of filamentary material by the band spinning process which will be free from the foregoing and other disadvantages and which will be especially simple in construction and etlicient in operation.

A further object of this invention is to provide an apparatus for the production of lamentary material by the band spinning process in which the filament-forming material will reach the spinning jet free from unmelted material and at a substantially uniform temperature.

Other objects of this invention, together with certain details of construction and combinations of parts, will be apparent from the following detailed description and claim.

According to the present invention, the aforementioned difficulties previously encountered in the production of iilamentary materials by the band spinning process are Preferably, this means is positioned at a point spaced from 2,717,418 Patented Sept. 13, 1955 fer surface per unit length of the melting tube in contact with the filament-forming material along a length ofthe passageway adjacent to the discharge end of the melting Y tube to such an extent that it is greater than the heat transfer surface per unit length of the melting tube in contact with the filament-forming material along the remainder of the passageway. Advantageously, the heat transfer surface per unit length of the melting tube is increased along at least about 25% and preferably at least about 50% of the length of the passageway, and the heat transfer surface per unit length of the melting tube along this length is increased by an averageV factor of at least about and preferably at least about 500% over the heat transfer surface along an equal length of the remainder of said passageway. The means employed for increasing the heat transfer surface per unit vlength of the melting tube may advantageously also act to reduce the thickness of at least a portionof the filament-forming material in contact with said heating surface further tok band of filament-forming material so that if the length of the unmelted portion of said band becomes excessive, as pointed out above, the tip of the band will contact said means and bebrought rapidly to the melting temperature.

about 25 to` 50% of the total length of the melting tube away from the discharge end of the melting tube. A single means may serve both to increase the heat transfer surface per unit length of the melting tube and to melt the unmelted tip of the band of filament-forming material if the length of the unmelted Aportion of said band becomes excessive.

The means for increasing the heattransfer surface per unit length of the melting tube may be integralwith or` separate from the melting tube. The passageway through the melting tube may have a uniform cross-sectional area throughout its length or it may be contoured to cooperate with the means operatively connected thereto to obtain the p desired increase in the heat transfer surface. l.

Preferred embodiments of this invention are show n in the accompanying drawings wherein Fig. l is a longitudinal cross-sectional View of one of band spinning apparatus,

Figs. 2 and 3 are transverse cross-sectional views, on an enlarged scale, taken along the lines 2-2 and 3 3, respectively, in Fig. l of the drawings,

Fig. 4 is a longitudinal cross-'sectional view of another form of band spinning apparatus,'and p Figs. 5 and.6 are transverse cross-sectional views, on an enlarged scale, taken along the lines 5-5 and 6 6, respectively, in Fig. 4 of the drawings.

Referring now to Figs. l to 3 of the drawings wherein one embodiment of this invention is illustrated, the reference numeral 11 designates generally an elongated melting tube having a passageway 12 of rectangular crosssection extending longitudinally thereof. The melting tube 11 is enclosed within a jacket 13 through which a heating medium is passed to raise the temperature of the melting tube 11, and the whole assembly is lagged with a layer of insulation 14.

Toward the discharge end of the melting tube 11, the passageway 12 opens into a chamber 15 having a longitudinal conical cross-section. Positioned within the chamber 15 is a conical member 16 having a taper substantially equal to the taper of the wall of the chamber 15, which conical member 16 is spaced from the wall of said form fastened' by means 'of'pins 20 and inf which there may be positioned means, such'as a.plurality of screens, or'abed of sand, tolter solid'particles from the melted iilament= forming material. A spinning jet 21' having. spinning orices22'therein is releasably secured over the discharge end ofthe chamber 1S by means of 4a retaining ring 23" inthreaded engagement with the meltingtube 11. A'retaining; ring 24'in threaded engagement with the jacket 13fserves to bind themelting tube ll'and'jacket 13 in operative relationship.

To. feed a rectangular band Yof filament-formingmate'- rial: (not shown) having a cross-section approximately' equal to'the cross-section of the passageway 12`through saidJpassageway at a constantrate, there is provided a pair offeed rollers 25 and 26, at least one of which is positively driven by any suitable means (not shown). As the bandtraverses the passageway 12, the filament-forming material will gradually melt. If the band does not melt completely before enteringthe chamber 15; the tip of the unmelted material will strike the conical member 16' and will' be raised rapidly to thel melting temperature. The melted 'filament-forming material, together with any unmelted'particles of said'material therein, will then yllow through the restricted annular passageway 17, wherein, owing to Ythe increased surface available for heat transfer and the reduced thickness of said material in said annular 5 passageway, the melting of said filament-forming material will be completed and all of the melted material-'will be brought uniformly tothe proper temperaturefor spinning. Frorn the annular passageway 17', the melted lilament-forming material will ow into andk through the chamber 18 and then through the spinning orifices 22' to produce iilarnentaryl materials of' uniform denier.

Referring now to Figs. 4 to 6 of the drawings, whereinanother embodiment of this invention is illustrated, the reference numeral 31 designates generally an elongated melting tube having a passageway 32 'of rectangular crosssection extending longitudinally thereof. The melting tube 31' ispositioned within a jacket 33y through which a heating, medium ispassed to raise the temperature of the melting tube 31, and the whole assembly is lagged with a` layer of insulation 34.

Toward'the discharge end of the-melting tube 31 one wall ofthe passageway 32 is provided-with a number of longitudinal ridges 35 integral with the melting tube 31' secured over the discharge end of the chamber 36. by

means of a retaining ring 39.in threaded engagementwith 4f the melting tube 31. A'retaning ring 41 in threaded engagementr*withethe-A jacket 33-serves to -hold the melting tube 31 and the jacket 33 inoperative relationship.

To feed a rectangular band of filament-forming material (not shown) having a cross-section approximately equal to the cross-section of the passageway 32 through said passageway at a constant*A rate, there is provided a pair of feed-rolls 42 -and 43,1at1least one of which is positively driven by any suitable means (not shown). As the bandtraverses Vthe passagewayl 32;'- the'lament-forrning'material willgraduallyvmelt' Ifthe band does not melt completely before reachingtheridges 35,' the tip of the unmelted material will strike said ridges and will be raisedrapidly'torthefmeltingitemperature. The-melted filament-forming materiahtogether with any unmelted particles of said materialtliereing' will" then flow between the ridges 35, wherein, owing to the increased surface available for heat transfer, the melting of said filamenti formingmateriall will;becompletedandall of the melted material*willb'ebroughtunifrmly tof--the proper temperaturefforf spinning: From"th"evpassageway 32, the melted filament-forming material: willl2 ow into and througheth'echamber. 36`-and`itl1enl through -the spinning orifices 38i-toproduce' fl'amentaryf materials of uniform denier.V

It isi tofbe-"understood-` tl'iat the foregoing detailed descriptionf is giveny merely 'byw-ayo illustration and that many variations-may yHemadetherein without departing from theI spiritiof our invention?- Having described A'our invention; what we desire to securek by lette'rs'fPatent is:

In an-apparatu's -or'thez preparation of lamentary materials by the bandfspinningprocess, rolls for feeding a band of filament-forming material, a melting tube having a' passageway vextendingtherethrough adapted to receive said b'andfromsaid rolls, a= jackebfor the passage of heating uid, extendingth'e length of :said tube, for uniformly heating said tube to melt Athe filament-forming material,Y andfa. plurality of ridges extending longitudinally of the passageway in the lwervportion thereof adjaeentfftoLtheJ-dischrgteiendoffthelmelting tube for increasing:the.:heattransfertsurfacelper unit length of the meltingltbeinf Contact withlthefilament-forming material-b'ylat least- 100 %y as fcomparedlwith the'heat transfer surface per?unittllngthflinI-theremainder of said tube wherebylalllof fthe filament-forming material will be melted-and Twill be zbroughtuniformly 'to/ the -proper temperature forf'spinning-.j

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